Molecular Characterization of Bovine Rotaviruses in Pakistan

Abstract

Background: Group A bovine Rotaviruses (BRV) are one of the main factors of neonatal calf diarrhea and mortality around the world. The current study was carried out to assess the genetics of BRV circulating in the Pakistani livestock and characterize the antigenic genes of Rotavirus contributing towards calf diarrhea. Methods: A total of 200 fecal samples were collected from diarrheic buffalo and cattle calves from ten districts of Punjab, Pakistan. Samples were selected on the basis of agro-ecological zones of the province. Fecal samples were analyzed for the presence of BRV using Ag-capture ELISA. Positive samples were subjected to PCR for the amplification of VP4 and VP6 genes and subsequent sequencing. Phylodynamics was performed to infer genetic clustering and evolutionary distances of characterized strains of BRV in accordance to the BRV available publically. Results: In ELISA, a total of 12 calf samples (5 cattle and 7 buffalo), 6%, were found positive. The sequencing and phylogenetic analysis of both genes showed that Pakistani BRV (BRV/QOL/13) depicted maximum identity (98%) of the VP4 gene with Indian BRV VP4 gene. Pakistani BRV VP6 gene (Pakistan/MM85/QOL) showed maximum identity of 98% with Indian BRV A VP6 gene (accession No. JF720873, EF200565). Conclusions: Bovine rotavirus presents 6% of calf diarrhea in Pakistani cattle and buffalo samples. The VP4 and VP6 genes show closed relationships with bovine rotavirus reported from Indian isolates.